She is the only one who can lead investigators to the truth about what happened to Caylee, who has been missing for 79 days, an agency spokesman said.

Until now, investigators did not call Casey Anthony a suspect, usually calling her a "person of interest."

But Capt. Angelo Nieves of the sheriff?s office said Casey Anthony is a suspect because of the evidence the agency has received from the FBI indicating there was a high probability that Caylee?s body was in her mother's trunk. He also said she has repeatedly lied to investigators.

"Well, she was the last person to person to see her daughter, and we are continuing to follow up on this information, and granted she would be a suspect," Nieves said.

Casey Anthony is out on bond on a variety of charges, from child neglect to check fraud. She initially told investigators her daughter was last with a baby sitter.

Investigators also pointed out that they have not given up on the search for Caylee.

Attorney Jose Baez, Casey Anthony?s attorney, said it doesn?t make a difference whether investigators call her a "person of interest" or a "suspect." He declined a request for a further interview.

The attorney for George and Cindy Anthony said he had not talked to them to get their reaction to their daughter being named a suspect.

Anthony visited Baez on Thursday, while her ex-fiance, Jesse Grund, sat down with Matt Lauer on the "Today" show.

Lauer asked Grund if his former fiancee, Casey Anthony, is capable of hurting Caylee.

"The Casey I knew, no. But no one knows the real Casey," Grund said.

Grund also called on Anthony to stop destroying people's lives.

"We're all done with it we're all done with hearing your lies and your stories that don't make sense over and over again. Tell the truth about what happened," he said.

A pre-trial hearing is slated for Nov. 5. The trial is set for Nov. 17.